Most people don’t realize that you can win an FFA match even with a negative K/D. It doesn’t matter how many times you die, it just matters how many kills you get. (For example, you can go 15k-0d, and get a Perfection; but if I go 25k-26d, then I win, and you lose, and you can polish your Perfection medal as you drop down in rank.)
So what does that mean? Well, a couple of things:
(1) Don’t play defensively. Be aggressive. Take chances. Challenge enemies to gun battles. It’s a race to 25 kills, so you can’t be hanging back, waiting your turn.
(2) Doesn’t that mean other players will get there faster, if you keep getting killed? Well, no, not really. On average, your deaths will be spread out across all the other players. Get killed one time by five different players, and they each only get 1 point. But if you kill each of them just once, you’ve got 5 points.
(3) Don’t keep trying to beat the best player. I know, your ego wants you to take him down. But even if you finally get him after five tries, he’s got 5 points and you’ve got 1. Congrats, you’re losing now. Instead, avoid him, and go after the worst players. Kill them over and over again. Congrats, you’re winning now.
(4) Search for ongoing gun battles. The strategy for FFA is generally the opposite of Team Slayer. Let two other people fight it out and then you ambush the victor, who will be already weakened. Don’t necessarily try to intercede, because then you’re making yourself one of the primary combatants and inviting other players to ambush you.
(5) What if someone else is also ambushing the victor? No problem. Turn your gun on him instead. He’ll probably just try to finish his ambush, so that he scores a point before he dies… which means you’ll get a clean kill without losing any health or armor.
(6) Oh, and one more thing: Use grenades. Lots of them. There’s no friendly fire in FFA, so spam away. You’ll steal so many kills, they’re be calling the police.